The phrase "to it" can have various synonyms, depending on the context of how it is used. In the case of being productive or completing a task, some possible alternatives include "get started," "begin," or "embark on." When it comes to expressing determination or a strong commitment towards something, one might use words such as "dedicated," "committed," or "resolved." Alternately, when discussing completing something in a timely manner, possible synonyms could include "on schedule," "according to plan," or "as expected." Whatever the situation, there are a multitude of possible words and phrases that can be used as substitutes for the term "to it".